The NSA peeks and pries into our lives in countless ways, violating our privacy and ignoring the Fourth Amendment. But a former NSA technical chief says one agency activity endangers Americans more than the rest: the routine sharing of warrantless data with state and local law enforcement.

In an interview earlier this month, William Binney called NSA information sharing “the most threatening situation to our constitutional republic since the Civil War.”

Binney served as Technical Director of the World Geopolitical and Military Analysis Reporting Group for the NSA and was considered one of the best analysts and code breakers ever employed by the agency. He quit abruptly after 9/11 due to the NSA’s increasing focus on domestic spying in the wake of the attacks.

I left in October 2001 because they started spying on everybody and assembling information on everyone in the United States, and it went first with phone numbers and then went into the Internet later on and very shortly thereafter. So it was very clear to me they were pulling together all this knowledge like a super Stasi-State. NSA was becoming the new Stasi agency.

Reuters revealed the extent of NSA data sharing with state and local law enforcement in an August 2013 article. According to documents obtained by the news agency, the NSA passes information through a formerly secret DEA unit known Special Operations Divisions and the cases “rarely involve national security issues.” Almost all of the information involves regular criminal investigations.

Binney said the feds share information gathered without a warrant and direct the local police force to make an arrest. Using a process known as “parallel construction,” investigators then build their case using normal policing techniques, getting warrants for information they’ve already obtained. The process serves to hide the illegally gathered information, creating the illusion of a legitimate case.

“You use that data to substitute for the NSA data that was originally used to arrest them. And you substitute the parallel constructed data in the courtroom, which I’ve called perjury. They’re lying to the courts and they’re subverting our entire judicial process,” he said.

In late 2013, the Washington Post reported that NSA is “gathering nearly 5 billion records a day on the whereabouts of cellphones around the world.” This includes location data on “tens of millions” of Americans each year – without a warrant.

We also know that, through fusion centers, state and local law enforcement act as information recipients from various federal departments under Information Sharing Environment (ISE). We also know that ISE partners include the Office of Director of National Intelligence, which is an umbrella covering 17 federal agencies and organizations, including the NSA. While fighting terrorism was always held out as the reason for dragnet spying, Binney said it was bound to be abused.

“That’s what happens when you allow this kind of assembly of information – that’s so much power. That’s like J. Edgar Hoover on super-steroids,” he said. “This is not compatible with any form of democracy at all.”

The good news is that OffNow has a strategy to counter the practical effects of data sharing. While a state can’t stop the federal government from gathering information, it can prohibit the state from obtaining it and make it inadmissible in court. Even though state and local law enforcement work with the feds to conceal its origins, history shows that specifically prohibiting the state from obtaining data can limits its usefulness. (More on that HERE.)

The Electronic Data Privacy Act prohibits state agencies from “obtaining” data collected without a warrant with a few exceptions. This includes phone records and conversations, location data, emails and Internet history. The legislation puts limits on state and local law enforcement data collection, requiring a warrant in most cases, and it also legally puts the kibosh on parallel construction.

This is a great opportunity for you to take action and protect privacy and due process in your state. Contact your state representative and senator and ask them to introduce the Electronic Data Privacy Protection Act. Download the legislation at http://www.offnow.org/electronic_data_privacy_act.